Provanna


Provanna is a genus of sea snails, marine gastropod mollusks in the family Provannidae.
The species was named after Dall's first wife.
This is a very old genus with species already existing in Cretaceous seep deposits off Japan. The Caribbean and the Pacific fauna were isolated about 3 million years ago by the closure of the Central American Isthmus.

Description

The apical whorls of the protoconch are lacking through decollation. The opening is then sealed with a calcareous plug. The sculpture of the ovate fusiform shell shows scattered sigmoidal axial ribs that are crossed by spiral cords. The whorls are broad.

Habitat

They are common in hydrothermal vents, hydrocarbon cold seeps and on deep-water food-falls, depending on the species. Most species feed on filamentous bacteria, while others feed on detritus.

Species

Species within the genus Provanna include:Provanna abyssalis Okutani & Fujikura, 2002Provanna admetoides Warén & Ponder, 1991
Several fossil species have been described, predominantly identified from hydrocarbon seep deposits, including:Provanna antiqua Squires & Goedert, 1995 Provanna marshalli Saether, Little & Campbell, 2010Provanna nakagawaensis Kaim, Jenkins & Hikida, 2009Provanna tappuensis Kaim, Jenkins & Warén, 2008
There also are several fossil species known, but not formally described and named, from Central America, Japan, and possibly the Philippines.
;Species brought into synonymy:Provanna marianensis Okutani & Fujikura, 1990: synonym of ''Desbruyeresia marianensis''